If a structure, such as a machine or a part of a product, has a defect, such as a crack, a void, or a recess, there is a risk that the machine or part will become inoperable due to the defect. Thus, it is desired that the part having such a defect is eliminated or replaced by detecting the presence of such a defect in advance of the machine or part becoming inoperable. For example, aircraft skins and other manufactured components are frequently made from laminates, which are layers of material adhered together by layers of adhesive, such as, but not limited to, sealant, epoxy, and glue, interposing the layers of material. Laminates can delaminate when the adhesive layers can no longer adhere the layers of material together. Typically, delamination does not occur spontaneously, but rather, it occurs after voids have formed in the adhesive layers. In addition to concerns about delamination due to voids, laminates can also fail due to cracks. Thus, it is desirable to examine by non-destructive means the internal structure of a laminate to search for voids, cracks, and other internal defects before the laminate fails.
It is desirable that the examination of an object occurs in situ. In situ examination of a component can typically be done more rapidly and inexpensively than non-in situ because there it requires less disassembly and reassembly of the system. It is also desirable that the apparatus used for examining the component be readily transportable.
Thus, a heretofore-unaddressed need exists in the industry to address the aforementioned deficiencies and inadequacies.